if_tun.c revision 1.51.4.1
1 /* $NetBSD: if_tun.c,v 1.51.4.1 2002/05/16 03:57:33 gehenna Exp $ */ 2 3 /* 4 * Copyright (c) 1988, Julian Onions <jpo (at) cs.nott.ac.uk> 5 * Nottingham University 1987. 6 * 7 * This source may be freely distributed, however I would be interested 8 * in any changes that are made. 9 * 10 * This driver takes packets off the IP i/f and hands them up to a 11 * user process to have its wicked way with. This driver has its 12 * roots in a similar driver written by Phil Cockcroft (formerly) at 13 * UCL. This driver is based much more on read/write/poll mode of 14 * operation though. 15 */ 16 17 #include <sys/cdefs.h> 18 __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.51.4.1 2002/05/16 03:57:33 gehenna Exp $"); 19 20 #include "tun.h" 21 22 #include "opt_inet.h" 23 #include "opt_ns.h" 24 25 #include <sys/param.h> 26 #include <sys/proc.h> 27 #include <sys/systm.h> 28 #include <sys/mbuf.h> 29 #include <sys/buf.h> 30 #include <sys/protosw.h> 31 #include <sys/socket.h> 32 #include <sys/ioctl.h> 33 #include <sys/errno.h> 34 #include <sys/syslog.h> 35 #include <sys/select.h> 36 #include <sys/poll.h> 37 #include <sys/file.h> 38 #include <sys/signalvar.h> 39 #include <sys/conf.h> 40 41 #include <machine/cpu.h> 42 43 #include <net/if.h> 44 #include <net/if_ether.h> 45 #include <net/netisr.h> 46 #include <net/route.h> 47 48 49 #ifdef INET 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #include <netinet/in_var.h> 53 #include <netinet/ip.h> 54 #include <netinet/if_inarp.h> 55 #endif 56 57 #ifdef NS 58 #include <netns/ns.h> 59 #include <netns/ns_if.h> 60 #endif 61 62 #include "bpfilter.h" 63 #if NBPFILTER > 0 64 #include <sys/time.h> 65 #include <net/bpf.h> 66 #endif 67 68 #include <net/if_tun.h> 69 70 #define TUNDEBUG if (tundebug) printf 71 int tundebug = 0; 72 73 extern int ifqmaxlen; 74 void tunattach __P((int)); 75 LIST_HEAD(, tun_softc) tun_softc_list; 76 static struct simplelock tun_softc_lock; 77 78 int tun_ioctl __P((struct ifnet *, u_long, caddr_t)); 79 int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 80 struct rtentry *rt)); 81 int tun_clone_create __P((struct if_clone *, int)); 82 void tun_clone_destroy __P((struct ifnet *)); 83 84 struct if_clone tun_cloner = 85 IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); 86 87 static void tunattach0 __P((struct tun_softc *)); 88 static void tuninit __P((struct tun_softc *)); 89 #ifdef ALTQ 90 static void tunstart __P((struct ifnet *)); 91 #endif 92 static struct tun_softc *tun_find_unit __P((dev_t)); 93 94 dev_type_open(tunopen); 95 dev_type_close(tunclose); 96 dev_type_read(tunread); 97 dev_type_write(tunwrite); 98 dev_type_ioctl(tunioctl); 99 dev_type_poll(tunpoll); 100 101 const struct cdevsw tun_cdevsw = { 102 tunopen, tunclose, tunread, tunwrite, tunioctl, 103 nostop, notty, tunpoll, nommap, 104 }; 105 106 void 107 tunattach(unused) 108 int unused; 109 { 110 111 simple_lock_init(&tun_softc_lock); 112 LIST_INIT(&tun_softc_list); 113 if_clone_attach(&tun_cloner); 114 } 115 116 int 117 tun_clone_create(ifc, unit) 118 struct if_clone *ifc; 119 int unit; 120 { 121 struct tun_softc *sc; 122 123 sc = malloc(sizeof(struct tun_softc), M_DEVBUF, M_WAITOK); 124 (void)memset(sc, 0, sizeof(struct tun_softc)); 125 126 (void)snprintf(sc->tun_if.if_xname, sizeof(sc->tun_if.if_xname), 127 "%s%d", ifc->ifc_name, unit); 128 sc->tun_unit = unit; 129 simple_lock_init(&sc->tun_lock); 130 131 tunattach0(sc); 132 133 simple_lock(&tun_softc_lock); 134 LIST_INSERT_HEAD(&tun_softc_list, sc, tun_list); 135 simple_unlock(&tun_softc_lock); 136 137 return (0); 138 } 139 140 void 141 tunattach0(sc) 142 struct tun_softc *sc; 143 { 144 struct ifnet *ifp = (void *)sc; 145 146 sc->tun_flags = TUN_INITED; 147 148 ifp = &sc->tun_if; 149 ifp->if_softc = sc; 150 ifp->if_mtu = TUNMTU; 151 ifp->if_ioctl = tun_ioctl; 152 ifp->if_output = tun_output; 153 #ifdef ALTQ 154 ifp->if_start = tunstart; 155 #endif 156 ifp->if_flags = IFF_POINTOPOINT; 157 ifp->if_snd.ifq_maxlen = ifqmaxlen; 158 ifp->if_collisions = 0; 159 ifp->if_ierrors = 0; 160 ifp->if_oerrors = 0; 161 ifp->if_ipackets = 0; 162 ifp->if_opackets = 0; 163 ifp->if_dlt = DLT_NULL; 164 IFQ_SET_READY(&ifp->if_snd); 165 if_attach(ifp); 166 if_alloc_sadl(ifp); 167 #if NBPFILTER > 0 168 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 169 #endif 170 } 171 172 void 173 tun_clone_destroy(ifp) 174 struct ifnet *ifp; 175 { 176 struct tun_softc *tp = (void *)ifp; 177 struct proc *p; 178 179 simple_lock(&tun_softc_lock); 180 simple_lock(&tp->tun_lock); 181 LIST_REMOVE(tp, tun_list); 182 simple_unlock(&tp->tun_lock); 183 simple_unlock(&tun_softc_lock); 184 185 if (tp->tun_flags & TUN_RWAIT) { 186 tp->tun_flags &= ~TUN_RWAIT; 187 wakeup((caddr_t)tp); 188 } 189 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 190 if (tp->tun_pgrp > 0) 191 gsignal(tp->tun_pgrp, SIGIO); 192 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 193 psignal(p, SIGIO); 194 } 195 selwakeup(&tp->tun_rsel); 196 197 #if NBPFILTER > 0 198 bpfdetach(ifp); 199 #endif 200 if_detach(ifp); 201 202 free(tp, M_DEVBUF); 203 } 204 205 static struct tun_softc * 206 tun_find_unit(dev) 207 dev_t dev; 208 { 209 struct tun_softc *tp; 210 int unit = minor(dev); 211 212 simple_lock(&tun_softc_lock); 213 LIST_FOREACH(tp, &tun_softc_list, tun_list) 214 if (unit == tp->tun_unit) 215 break; 216 if (tp) 217 simple_lock(&tp->tun_lock); 218 simple_unlock(&tun_softc_lock); 219 220 return (tp); 221 } 222 223 /* 224 * tunnel open - must be superuser & the device must be 225 * configured in 226 */ 227 int 228 tunopen(dev, flag, mode, p) 229 dev_t dev; 230 int flag, mode; 231 struct proc *p; 232 { 233 struct ifnet *ifp; 234 struct tun_softc *tp; 235 int error; 236 237 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 238 return (error); 239 240 if (NTUN < 1) 241 return (ENXIO); 242 243 tp = tun_find_unit(dev); 244 245 if (!tp) 246 return (ENXIO); 247 248 if (tp->tun_flags & TUN_OPEN) { 249 simple_unlock(&tp->tun_lock); 250 return (EBUSY); 251 } 252 253 ifp = &tp->tun_if; 254 tp->tun_flags |= TUN_OPEN; 255 TUNDEBUG("%s: open\n", ifp->if_xname); 256 simple_unlock(&tp->tun_lock); 257 return (0); 258 } 259 260 /* 261 * tunclose - close the device - mark i/f down & delete 262 * routing info 263 */ 264 int 265 tunclose(dev, flag, mode, p) 266 dev_t dev; 267 int flag; 268 int mode; 269 struct proc *p; 270 { 271 int s; 272 struct tun_softc *tp; 273 struct ifnet *ifp; 274 275 tp = tun_find_unit(dev); 276 277 /* interface was "destroyed" before the close */ 278 if (tp == NULL) 279 return (0); 280 281 ifp = &tp->tun_if; 282 283 tp->tun_flags &= ~TUN_OPEN; 284 285 /* 286 * junk all pending output 287 */ 288 s = splnet(); 289 IFQ_PURGE(&ifp->if_snd); 290 splx(s); 291 292 if (ifp->if_flags & IFF_UP) { 293 s = splnet(); 294 if_down(ifp); 295 if (ifp->if_flags & IFF_RUNNING) { 296 /* find internet addresses and delete routes */ 297 struct ifaddr *ifa; 298 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 299 #ifdef INET 300 if (ifa->ifa_addr->sa_family == AF_INET) { 301 rtinit(ifa, (int)RTM_DELETE, 302 tp->tun_flags & TUN_DSTADDR 303 ? RTF_HOST 304 : 0); 305 } 306 #endif 307 } 308 } 309 splx(s); 310 } 311 tp->tun_pgrp = 0; 312 selwakeup(&tp->tun_rsel); 313 314 TUNDEBUG ("%s: closed\n", ifp->if_xname); 315 simple_unlock(&tp->tun_lock); 316 return (0); 317 } 318 319 static void 320 tuninit(tp) 321 struct tun_softc *tp; 322 { 323 struct ifnet *ifp = &tp->tun_if; 324 struct ifaddr *ifa; 325 326 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 327 328 ifp->if_flags |= IFF_UP | IFF_RUNNING; 329 330 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 331 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 332 #ifdef INET 333 if (ifa->ifa_addr->sa_family == AF_INET) { 334 struct sockaddr_in *sin; 335 336 sin = satosin(ifa->ifa_addr); 337 if (sin && sin->sin_addr.s_addr) 338 tp->tun_flags |= TUN_IASET; 339 340 if (ifp->if_flags & IFF_POINTOPOINT) { 341 sin = satosin(ifa->ifa_dstaddr); 342 if (sin && sin->sin_addr.s_addr) 343 tp->tun_flags |= TUN_DSTADDR; 344 } 345 } 346 #endif 347 } 348 349 return; 350 } 351 352 /* 353 * Process an ioctl request. 354 */ 355 int 356 tun_ioctl(ifp, cmd, data) 357 struct ifnet *ifp; 358 u_long cmd; 359 caddr_t data; 360 { 361 int error = 0, s; 362 struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); 363 364 simple_lock(&tp->tun_lock); 365 366 s = splnet(); 367 switch(cmd) { 368 case SIOCSIFADDR: 369 tuninit((struct tun_softc *)(ifp->if_softc)); 370 TUNDEBUG("%s: address set\n", ifp->if_xname); 371 break; 372 case SIOCSIFDSTADDR: 373 tuninit((struct tun_softc *)(ifp->if_softc)); 374 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 375 break; 376 case SIOCSIFBRDADDR: 377 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 378 break; 379 case SIOCSIFMTU: { 380 struct ifreq *ifr = (struct ifreq *) data; 381 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 382 error = EINVAL; 383 break; 384 } 385 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 386 ifp->if_mtu = ifr->ifr_mtu; 387 break; 388 } 389 case SIOCADDMULTI: 390 case SIOCDELMULTI: { 391 struct ifreq *ifr = (struct ifreq *) data; 392 if (ifr == 0) { 393 error = EAFNOSUPPORT; /* XXX */ 394 break; 395 } 396 switch (ifr->ifr_addr.sa_family) { 397 398 #ifdef INET 399 case AF_INET: 400 break; 401 #endif 402 403 default: 404 error = EAFNOSUPPORT; 405 break; 406 } 407 break; 408 } 409 case SIOCSIFFLAGS: 410 break; 411 default: 412 error = EINVAL; 413 } 414 splx(s); 415 simple_unlock(&tp->tun_lock); 416 return (error); 417 } 418 419 /* 420 * tun_output - queue packets from higher level ready to put out. 421 */ 422 int 423 tun_output(ifp, m0, dst, rt) 424 struct ifnet *ifp; 425 struct mbuf *m0; 426 struct sockaddr *dst; 427 struct rtentry *rt; 428 { 429 struct tun_softc *tp = ifp->if_softc; 430 struct proc *p; 431 #ifdef INET 432 int s; 433 int error; 434 #endif 435 ALTQ_DECL(struct altq_pktattr pktattr;) 436 437 simple_lock(&tp->tun_lock); 438 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 439 440 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 441 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 442 tp->tun_flags); 443 m_freem (m0); 444 simple_unlock(&tp->tun_lock); 445 return (EHOSTDOWN); 446 } 447 448 /* 449 * if the queueing discipline needs packet classification, 450 * do it before prepending link headers. 451 */ 452 IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr); 453 454 #if NBPFILTER > 0 455 if (ifp->if_bpf) { 456 /* 457 * We need to prepend the address family as 458 * a four byte field. Cons up a dummy header 459 * to pacify bpf. This is safe because bpf 460 * will only read from the mbuf (i.e., it won't 461 * try to free it or keep a pointer to it). 462 */ 463 struct mbuf m; 464 u_int32_t af = dst->sa_family; 465 466 m.m_next = m0; 467 m.m_len = sizeof(af); 468 m.m_data = (char *)⁡ 469 470 bpf_mtap(ifp->if_bpf, &m); 471 } 472 #endif 473 474 switch(dst->sa_family) { 475 #ifdef INET 476 case AF_INET: 477 if (tp->tun_flags & TUN_PREPADDR) { 478 /* Simple link-layer header */ 479 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 480 if (m0 == NULL) { 481 IF_DROP(&ifp->if_snd); 482 simple_unlock(&tp->tun_lock); 483 return (ENOBUFS); 484 } 485 bcopy(dst, mtod(m0, char *), dst->sa_len); 486 } 487 /* FALLTHROUGH */ 488 case AF_UNSPEC: 489 s = splnet(); 490 IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error); 491 if (error) { 492 splx(s); 493 ifp->if_collisions++; 494 return (error); 495 } 496 splx(s); 497 ifp->if_opackets++; 498 break; 499 #endif 500 default: 501 m_freem(m0); 502 simple_unlock(&tp->tun_lock); 503 return (EAFNOSUPPORT); 504 } 505 506 if (tp->tun_flags & TUN_RWAIT) { 507 tp->tun_flags &= ~TUN_RWAIT; 508 wakeup((caddr_t)tp); 509 } 510 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 511 if (tp->tun_pgrp > 0) 512 gsignal(tp->tun_pgrp, SIGIO); 513 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 514 psignal(p, SIGIO); 515 } 516 selwakeup(&tp->tun_rsel); 517 simple_unlock(&tp->tun_lock); 518 return (0); 519 } 520 521 /* 522 * the cdevsw interface is now pretty minimal. 523 */ 524 int 525 tunioctl(dev, cmd, data, flag, p) 526 dev_t dev; 527 u_long cmd; 528 caddr_t data; 529 int flag; 530 struct proc *p; 531 { 532 int s; 533 struct tun_softc *tp; 534 535 tp = tun_find_unit(dev); 536 537 /* interface was "destroyed" already */ 538 if (tp == NULL) 539 return (ENXIO); 540 541 switch (cmd) { 542 case TUNSDEBUG: 543 tundebug = *(int *)data; 544 break; 545 546 case TUNGDEBUG: 547 *(int *)data = tundebug; 548 break; 549 550 case TUNSIFMODE: 551 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 552 case IFF_POINTOPOINT: 553 case IFF_BROADCAST: 554 s = splnet(); 555 if (tp->tun_if.if_flags & IFF_UP) { 556 splx(s); 557 simple_unlock(&tp->tun_lock); 558 return (EBUSY); 559 } 560 tp->tun_if.if_flags &= 561 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 562 tp->tun_if.if_flags |= *(int *)data; 563 splx(s); 564 break; 565 default: 566 simple_unlock(&tp->tun_lock); 567 return (EINVAL); 568 break; 569 } 570 break; 571 572 case TUNSLMODE: 573 if (*(int *)data) 574 tp->tun_flags |= TUN_PREPADDR; 575 else 576 tp->tun_flags &= ~TUN_PREPADDR; 577 break; 578 579 case FIONBIO: 580 if (*(int *)data) 581 tp->tun_flags |= TUN_NBIO; 582 else 583 tp->tun_flags &= ~TUN_NBIO; 584 break; 585 586 case FIOASYNC: 587 if (*(int *)data) 588 tp->tun_flags |= TUN_ASYNC; 589 else 590 tp->tun_flags &= ~TUN_ASYNC; 591 break; 592 593 case FIONREAD: 594 s = splnet(); 595 if (tp->tun_if.if_snd.ifq_head) 596 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 597 else 598 *(int *)data = 0; 599 splx(s); 600 break; 601 602 case TIOCSPGRP: 603 tp->tun_pgrp = *(int *)data; 604 break; 605 606 case TIOCGPGRP: 607 *(int *)data = tp->tun_pgrp; 608 break; 609 610 default: 611 simple_unlock(&tp->tun_lock); 612 return (ENOTTY); 613 } 614 simple_unlock(&tp->tun_lock); 615 return (0); 616 } 617 618 /* 619 * The cdevsw read interface - reads a packet at a time, or at 620 * least as much of a packet as can be read. 621 */ 622 int 623 tunread(dev, uio, ioflag) 624 dev_t dev; 625 struct uio *uio; 626 int ioflag; 627 { 628 struct tun_softc *tp; 629 struct ifnet *ifp; 630 struct mbuf *m, *m0; 631 int error=0, len, s, index; 632 633 tp = tun_find_unit(dev); 634 635 /* interface was "destroyed" already */ 636 if (tp == NULL) 637 return (ENXIO); 638 639 index = tp->tun_if.if_index; 640 ifp = &tp->tun_if; 641 642 TUNDEBUG ("%s: read\n", ifp->if_xname); 643 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 644 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 645 simple_unlock(&tp->tun_lock); 646 return EHOSTDOWN; 647 } 648 649 tp->tun_flags &= ~TUN_RWAIT; 650 651 s = splnet(); 652 do { 653 IFQ_DEQUEUE(&ifp->if_snd, m0); 654 if (m0 == 0) { 655 if (tp->tun_flags & TUN_NBIO) { 656 splx(s); 657 simple_unlock(&tp->tun_lock); 658 return (EWOULDBLOCK); 659 } 660 tp->tun_flags |= TUN_RWAIT; 661 simple_unlock(&tp->tun_lock); 662 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 663 splx(s); 664 return (EINTR); 665 } else { 666 /* 667 * Maybe the interface was destroyed while 668 * we were sleeping, so let's ensure that 669 * we're looking at the same (valid) tun 670 * interface before looping. 671 */ 672 tp = tun_find_unit(dev); 673 if (tp == NULL || 674 tp->tun_if.if_index != index) { 675 splx(s); 676 if (tp) 677 simple_unlock(&tp->tun_lock); 678 return (ENXIO); 679 } 680 } 681 } 682 } while (m0 == 0); 683 splx(s); 684 685 while (m0 && uio->uio_resid > 0 && error == 0) { 686 len = min(uio->uio_resid, m0->m_len); 687 if (len != 0) 688 error = uiomove(mtod(m0, caddr_t), len, uio); 689 MFREE(m0, m); 690 m0 = m; 691 } 692 693 if (m0) { 694 TUNDEBUG("Dropping mbuf\n"); 695 m_freem(m0); 696 } 697 if (error) 698 ifp->if_ierrors++; 699 simple_unlock(&tp->tun_lock); 700 return (error); 701 } 702 703 /* 704 * the cdevsw write interface - an atomic write is a packet - or else! 705 */ 706 int 707 tunwrite(dev, uio, ioflag) 708 dev_t dev; 709 struct uio *uio; 710 int ioflag; 711 { 712 struct tun_softc *tp; 713 struct ifnet *ifp; 714 struct mbuf *top, **mp, *m; 715 struct ifqueue *ifq; 716 struct sockaddr dst; 717 int isr, error=0, s, tlen, mlen; 718 719 tp = tun_find_unit(dev); 720 721 /* interface was "destroyed" already */ 722 if (tp == NULL) 723 return (ENXIO); 724 725 ifp = &tp->tun_if; 726 727 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 728 729 if (tp->tun_flags & TUN_PREPADDR) { 730 if (uio->uio_resid < sizeof(dst)) { 731 simple_unlock(&tp->tun_lock); 732 return (EIO); 733 } 734 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 735 if (dst.sa_len > sizeof(dst)) { 736 /* Duh.. */ 737 char discard; 738 int n = dst.sa_len - sizeof(dst); 739 while (n--) 740 if ((error = uiomove(&discard, 1, uio)) != 0) { 741 simple_unlock(&tp->tun_lock); 742 return (error); 743 } 744 } 745 } else { 746 #ifdef INET 747 dst.sa_family = AF_INET; 748 #endif 749 } 750 751 if (uio->uio_resid < 0 || uio->uio_resid > TUNMTU) { 752 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 753 (unsigned long)uio->uio_resid); 754 simple_unlock(&tp->tun_lock); 755 return (EIO); 756 } 757 758 switch (dst.sa_family) { 759 #ifdef INET 760 case AF_INET: 761 ifq = &ipintrq; 762 isr = NETISR_IP; 763 break; 764 #endif 765 default: 766 simple_unlock(&tp->tun_lock); 767 return (EAFNOSUPPORT); 768 } 769 770 tlen = uio->uio_resid; 771 772 /* get a header mbuf */ 773 MGETHDR(m, M_DONTWAIT, MT_DATA); 774 if (m == NULL) { 775 simple_unlock(&tp->tun_lock); 776 return (ENOBUFS); 777 } 778 mlen = MHLEN; 779 780 top = 0; 781 mp = ⊤ 782 while (error == 0 && uio->uio_resid > 0) { 783 m->m_len = min(mlen, uio->uio_resid); 784 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 785 *mp = m; 786 mp = &m->m_next; 787 if (uio->uio_resid > 0) { 788 MGET (m, M_DONTWAIT, MT_DATA); 789 if (m == 0) { 790 error = ENOBUFS; 791 break; 792 } 793 mlen = MLEN; 794 } 795 } 796 if (error) { 797 if (top) 798 m_freem (top); 799 ifp->if_ierrors++; 800 simple_unlock(&tp->tun_lock); 801 return (error); 802 } 803 804 top->m_pkthdr.len = tlen; 805 top->m_pkthdr.rcvif = ifp; 806 807 #if NBPFILTER > 0 808 if (ifp->if_bpf) { 809 /* 810 * We need to prepend the address family as 811 * a four byte field. Cons up a dummy header 812 * to pacify bpf. This is safe because bpf 813 * will only read from the mbuf (i.e., it won't 814 * try to free it or keep a pointer to it). 815 */ 816 struct mbuf m; 817 u_int32_t af = AF_INET; 818 819 m.m_next = top; 820 m.m_len = sizeof(af); 821 m.m_data = (char *)⁡ 822 823 bpf_mtap(ifp->if_bpf, &m); 824 } 825 #endif 826 827 s = splnet(); 828 if (IF_QFULL(ifq)) { 829 IF_DROP(ifq); 830 splx(s); 831 ifp->if_collisions++; 832 m_freem(top); 833 simple_unlock(&tp->tun_lock); 834 return (ENOBUFS); 835 } 836 IF_ENQUEUE(ifq, top); 837 splx(s); 838 ifp->if_ipackets++; 839 schednetisr(isr); 840 simple_unlock(&tp->tun_lock); 841 return (error); 842 } 843 844 #ifdef ALTQ 845 /* 846 * Start packet transmission on the interface. 847 * when the interface queue is rate-limited by ALTQ or TBR, 848 * if_start is needed to drain packets from the queue in order 849 * to notify readers when outgoing packets become ready. 850 */ 851 static void 852 tunstart(ifp) 853 struct ifnet *ifp; 854 { 855 struct tun_softc *tp = ifp->if_softc; 856 struct mbuf *m; 857 struct proc *p; 858 859 if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) 860 return; 861 862 IFQ_POLL(&ifp->if_snd, m); 863 if (m != NULL) { 864 if (tp->tun_flags & TUN_RWAIT) { 865 tp->tun_flags &= ~TUN_RWAIT; 866 wakeup((caddr_t)tp); 867 } 868 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 869 if (tp->tun_pgrp > 0) 870 gsignal(tp->tun_pgrp, SIGIO); 871 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 872 psignal(p, SIGIO); 873 } 874 selwakeup(&tp->tun_rsel); 875 } 876 } 877 #endif /* ALTQ */ 878 /* 879 * tunpoll - the poll interface, this is only useful on reads 880 * really. The write detect always returns true, write never blocks 881 * anyway, it either accepts the packet or drops it. 882 */ 883 int 884 tunpoll(dev, events, p) 885 dev_t dev; 886 int events; 887 struct proc *p; 888 { 889 struct tun_softc *tp; 890 struct ifnet *ifp; 891 int s, revents = 0; 892 893 tp = tun_find_unit(dev); 894 895 /* interface was "destroyed" already */ 896 if (tp == NULL) 897 return (0); 898 899 ifp = &tp->tun_if; 900 901 s = splnet(); 902 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 903 904 if (events & (POLLIN | POLLRDNORM)) { 905 if (IFQ_IS_EMPTY(&ifp->if_snd) == 0) { 906 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 907 ifp->if_snd.ifq_len); 908 revents |= events & (POLLIN | POLLRDNORM); 909 } else { 910 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 911 selrecord(p, &tp->tun_rsel); 912 } 913 } 914 915 if (events & (POLLOUT | POLLWRNORM)) 916 revents |= events & (POLLOUT | POLLWRNORM); 917 918 splx(s); 919 simple_unlock(&tp->tun_lock); 920 return (revents); 921 } 922
Indexes created Mon Oct 20 08:09:54 GMT 2025